1. USEUCOM Science & Technology
Steve Spehn
Deputy Science Advisor
ECJ8-C, S&T Branch

2. USEUCOM S&T Challenges
Positioning, Navigation, and Timing (PNT) / Communications (PNT/C)
Integrated Air and Missile Defense (IAMD)
Anti-Access / Area-Denial (A2/AD)
Intelligence, Surveillance, & Reconnaissance (ISR)
Electromagnetic Spectrum Management (ESM)
Cyber
Command and Control (C2) Interoperability
Space Resiliency
Counter-Unmanned Aerial Systems (C-UAS)
Joint Reception, Staging, Onward-movement, and Integration (JRSOI)
Maritime Surface and Subsurface Operations
Arctic-related

3. USEUCOM Arctic Challenges
Awareness
Environmental Intelligence
Arctic Domain Awareness
Accessibility
Presence
Response
Connectivity
Command, Control, Communications
Data Exfiltration

4. Solution Domains Space Layer Stratosphere Troposphere Land-Based
Maritime Surface
Maritime Sub-Surface

5. The Stratosphere Defined (roughly)
The layer of the Earth’s atmosphere in which the air temperature rises with altitude as a result of absorption of the Sun’s ultraviolet radiation by the ozone layer.
Lower boundary is approximately:
18 km at the Equator;
10–13 km at mid-latitudes; and
8 km at the poles.
Upper boundary is approximately 50 km.
Layers of the atmosphere: troposphere, stratosphere, mesosphere and thermosphere.
Credit: Randy Russell, UCAR

6. Potential Stratospheric Solutions
S&T Challenge
Example Solutions
PNT/C
GPS augmentation; Cooperative, tiered, alternate PNT; Distributive timing; Communications gateway
IAMD
Sensing; Tracking
A2/AD
See PNT/C; Regional data connectivity; IoT gateway
ISR
UGS gateway; IoT gateway
Cyber
TBD
ESM
C2 Interoperability
Communications gateway; IoT gateway
Space Resiliency
Rapid augmentation; Interim reconstitution
C-UAS
Detection and tracking; C2 interdiction
JRSOI
Maritime Operations
Communications gateway

7. Stratospheric Ground Footprints
For a minimum elevation angle of 0° (i.e., the platform is above the observer’s horizon), the radius of the ground footprint increases by about 10 km for every 1 km increase in altitude, up to a maximum radius of about 800 km at 50 km altitude.

8. Stratospheric Ground Footprints
Altitude
50 km
40 km
30 km
20 km
Footprints for a Stratospheric platform over the Beaufort Sea with: elevation = 0° and altitude = {20, 30, 40, 50} km

9. Stratospheric Ground Footprints
For an altitude of 50 km, the radius of the ground footprint decreases rapidly as the elevation angle (i.e., the apparent position of the platform above the observer’s horizon) increases from 0° to 20°.

10. Stratospheric Ground Footprints
Elevation
0 °
5 °
10 °
15 °
20 °
Footprints for a Stratospheric platform over the Beaufort Sea with: elevation (el) = {0, 5, 10, 15, 20}° and altitude = 50 km

11. Stratospheric Compared to LEO
LEO (500 km)
LEO (200 km)
Strat (50 km)
Footprints for platforms over the Beaufort Sea with elevation = 0°

12. Stratosphere as a LEO Connector
Using a stratospheric platform at 50 km altitude to connect to a satellite in LEO extends the effective ground footprint in a way that, for LEO altitudes, mimics the ground footprint of a satellite at much higher altitude.

13. Stratospheric Combined with LEO
LEO (500 km)
Strat (50 km)
Footprints for platforms (Strat, LEO, and Combined) over the Beaufort Sea with elevation = 0°

14. Stratospheric Mesh Network
Footprints for seven Stratospheric platforms at altitude = 50 km and with elevation = 0°

15. The Stratosphere as a Solution Domain
Leverage small satellite technologies
Potential solution technologies:
GPS augmentation
Cooperative, tiered, alternate PNT
Distributive timing
Communications gateway
IAMD sensing and tracking
Regional data connectivity, to include unattended sensors
Rapid augmentation and interim reconstitution of space-based capabilities